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"Accessible from" sounds like a place or something that you can access it from. "The back garden is accessible from the kitchen."
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Mr ListerSep 28 '12 at 6:31

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Yeah, accessible from is more related to a location, place. But imho the question could be, why not for like for available1 for - 2 to
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Em1Sep 28 '12 at 6:37

"Accessible from" means you can get to it from somewhere. "Accessible to" means that it can be got at by something.
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Matt E. Эллен♦Sep 28 '12 at 9:28

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So the question should have been: why don't we use accessible by or accessible for.
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Mr ListerSep 28 '12 at 12:32